Clifford Chance (CC) and Osborne Clarke (OC) have advised on the first pre-let in a Farringdon office development that faced an uncertain future after the collapse of construction giant Carillion.

Digital advertising company The Trade Desk has agreed to move into the One Bartholomew Close building in Barts Square, which has undergone a £165m redevelopment.

Carillion, which went into liquidation this January, was previously the main contractor, but the construction giant's collapse forced developer Helical to arrange replacements to carry out the remaining work.

CC advised Helical and funder AshbyCapital on the pre-let, which will see the advertising company take over one quarter of the office space in the building. The magic circle firm fielded a team led by real estate partner Ian Painter, while an OC team led by real estate partner Nick Simpson advised The Trade Desk.

Painter said: "We have been working with Helical on Barts Square from initial establishment of the joint venture with The Baupost Group and the acquisition of the old hospital site back in 2011, through to this major pre-let. It has been fantastic to watch the transformation of the site and to support Helical and AshbyCapital in bringing this major London development to fruition."

As well as the 12-storey, 215,000 sq ft One Bartholomew building, the redevelopment includes 236  apartments, two other office spaces and 20,500 square feet of retail and restaurant space.

CC also recently advised Network Rail on the transfer of Carillion's Network Rail contracts to Amey Rail, a deal that saved hundreds of jobs following the construction company's collapse.